1. Field of the Invention
Dysphagia is a condition or symptom defined as a difficulty in swallowing. The present invention relates to a method for the standardized measurement of the quality or degree of dysphagia and a kit used for that method.
2. Background of the Art
Dysphagia, or difficulty in swallowing, is a condition or symptom which can be caused by many different conditions, injuries or diseases. Dysphagia can cause choking, aspiration of food or liquid into the lungs, incomplete administration of medication, and discomfort to the victims. These factors can at least discomfort a patient, but may also interfere with or complicate conventional treatment of patients. Among the many contributions to or causes of dysphagia are head injuries, Parkinsonism, Alzheimer's disease, muscular dystrophy, cerebral palsy, cancer, medication side effects, advanced HIV infections, gastrointestinal disorders, and brain tumors. It has been estimated that more than 10,000 patients a year choke to death as a result of dysphagia.
Dysphagia is a well-recognized condition and has been studied and addressed by doctors and nutritionists (Robertson, Helen M. And Pattillo, Margaret S., Journal of the Canadian Dietetic Association, Vol. 54, No. 4, Winter 1993). Such studies have noted that the condition is affected by the temperature, pH, viscosity, volume, size and shape of particulate matter in the ingested sample, and that these conditions can affect the likelihood of a bolus passing safely through the swallowing process.
Robertson et al. (supra) formulated test substances for the videofluoroscopy examination of the patient for visual examination of dysphagia effects on individual patients. An actual structural evaluation of the patient's dysphagia was observed under fluoroscopy. It was further noted in the preparation of the blended materials used during the fluoroscopic examination that the foods used were not by nature smooth and homogeneous, and that they may vary in cohesiveness, adhesiveness, viscosity and texture. It was noted that where materials exhibited the worst two-phase characteristics (fibrous materials in a liquid), the materials were further blended with whipped potato to produce smoother, more cohesive products. Various test points based upon viscosity (ranging from dry, crumbly material, 2000 cps, 800 cps, 250 cps and 100 cps) and texture (Dysphagia/Dental soft, Minced/chopped, and Puree') are intended to be identified on the food preparation menus offered to patients.
Felt, Pat and Anderson, Coleen, Nutritional Management of Oropharyngeal Dysphagia for the Adult Patient: A Therapist's Guide, 1990 describes the diagnosis and treatment of dysphagia, diets for dysphagia sufferers, and related matters. The publication noted that swallowing, and therefore dysphagia, occurs in three phases: the oral, pharyngeal and esophageal phases. The publication identifies and provides guidelines for the three phases, and identifies properties of the food or bolus which can attribute to the problem or relieve the problem. Amongst the properties are viscosity, elasticity, and particulateness. Diets based on nutritional requirements and physical properties are provided.
Womak, Pam and Pope, Jane Erwin, Solving the Mystery of Dysphagia, Dietary Manager," March 1992 describes the swallowing process and provides guidelines for the temporary diet management of the dysphagia patient. The viscosity and texture of the food as part of the rheologic evaluation of the food, as well as the seasoning and temperature, are emphasized.
Li, Brasseur, Kern and Dodds, Dysphagia, 7:17-30, 1992 made detailed viscosity measurements on barium sulfate mixtures for use in motility studies of the pharynx and esophagus. The mixtures also used flavorings. The viscosity of the mixtures was described with respect to the concentration of ingredients so that a standard viscosity could be provided for use in motility studies. Viscosity was the primary rheologic property considered for standardization, although viscosity was considered as a function of shear rate. The conclusion suggests that a test kit of bolus substances in which other rheologic characteristics (e.g., elasticity) are included would be of great clinical value.
Although treatment and diagnosis of dysphagia have been addressed, there is little standardization within the medical profession for evaluation of the condition, except by extreme methods such as fluoroscopic examination. In view of dramatic cost controls applied to medical treatment, such evaluations and diagnostic procedures would not likely be approved.